The figure you refer actually shows assumptions for 1, 2, 10, and/or 20 years after Program/Erase cycling 10k or 100k cycles at 55 degree Celsius. If the customer only program the flash once at 70C, it should meet datasheet specification which is 20 years data retention.
Thank you for your reply.
Your information was very helpful.
Is there an Arrhenius plot when programming flash once?
Sorry but we do not have the Arrhenius plot when programming only once.
Thank you for your reply again.